Answer
$\theta=693.6rad$
Work Step by Step
We have the car's initial linear speed $v_0=20m/s$, linear acceleration $a=1.5m/s^2$ and $t=8s$. The wheel's radius $r=0.3m$
In rolling motion, $v=v_T=r\omega$, so the car's initial angular speed is $$\omega_0=\frac{v_0}{r}=66.7rad/s$$
We also have $a=a_T=r\alpha$, so the car's angular acceleration is $$\alpha=\frac{a}{r}=5rad/s^2$$
The angular displacement of each wheel is $$\theta=\omega_0t+\frac{1}{2}\alpha t^2=693.6rad$$